The field of the invention relates generally to computer-implemented programs and, more particularly, to a computer-implemented system for continuous calibration of circuit breaker trip units and metering devices.
Many known methods and systems of circuit protection require monitoring of current flowing through the circuit. Such methods and systems use monitoring devices, known as trip units or metering devices, at various branch points in the hierarchy of the circuit. Accurate monitoring of current flowing through the circuit, by the trip units, is important to protect the circuit.
Many known trip units become less accurate at lower levels of the hierarchy. For instance, the accuracy of a trip unit detecting current for a feeder or branch breaker will generally be lower than the accuracy of a monitoring device detecting current for a trip unit located at a circuit main. Such lower level trip units are less accurate for several reasons. First, at lower levels in the circuit hierarchy, a lack of physical space may be prohibitive for accurate sensors. More accurate sensors may simply require more room than is permitted. Second, high accuracy sensors can be expensive and therefore difficult to provision to lower levels of the hierarchy where greater numbers of trip units are required. Third, over time lower level trip unit sensors may change in accuracy.
As a result, many known trip units cannot accurately detect the current at lower levels of circuit hierarchy. In many known systems and methods, trip units have error ranges indicating, by a percentage, the reliability of a given reading from given trip unit. Despite this information, accurate resolution of the current at lower level trip units is still difficult to determine. First, the current is only known within a range given by the error range. Second, over time, the error range may change.